The advantageous use of high protein supplements on late summer native range and Bermuda grass pastures has been well documented. The Oklahoma Gold supplementation program is widely used for fall-born replacement heifers and summer grazing of stocker cattle. Adding another management tool, late summer de-worming may pay additional dividends.
Oklahoma State University beef nutritionists studied the effects of de-worming and protein supplementation during late-summer on performance of fall-born heifers grazing native warm-season pastures. Forty Angus and Angus x Hereford heifers (average age = 270 days) were assigned to receive one of four treatment combinations: 1) no supplement, no de-wormer; 2) supplement, no de-wormer; 3) no supplement, de-wormed; and 4) supplement, and de-wormed. The de-wormer treatment (Ivermectin, 1% solution containing 10% clorsulon) was applied on July 25 and again on August 26. Protein supplemented heifers received the equivalent of 1 pound per head per day of cottonseed meal (41% crude protein, as fed basis) for 84 days beginning on July 29. Fecal egg counts were obtained from 5 heifers within each treatment combination at 28-day intervals. Fecal egg shedding was lower in de-wormed heifers throughout the treatment period.
Both protein supplementation and de-worming treatment resulted in improved weight gains during the treatment period. Late summer de-worming increased average daily gain by 0.29 lb/day. Feeding 1 pound of cottonseed meal increased average daily gain by 0.49 lb/day. Combining de-worming and protein supplement increased daily gain by 0.76 lb/day.
The effects of protein supplementation and de-worming are additive. However, some, although not all, of the additional weight gain due to supplementation was lost during the winter when heifers received a maintenance diet. Added weight gain that was attributed to de-worming heifers the previous summer was not lost during the winter. Source: Lalman and co-workers. 2004 OSU Animal Science Research Report.